A man jailed for at least 15 years for a violent home invasion murder will get a second go at acquittal after prosecutors admitted a significant jury error.

During an armed robbery targeting thousands of dollars in cash, 49-year-old father-of-two Warwick Hunter was stabbed to death in his western Sydney home.

Samir Chamma, 32, and John Hicks, 35, were found guilty of murder in 2023 after a jury found they were both knew there was a “non-fanciful probability” Hunter would be killed.

Chamma successfully had his conviction quashed and a retrial ordered by the NSW Court of Criminal Appeal today.

Crown prosecutors admitted they had not told jurors that a key witness, who cannot be legally identified, had received a discounted sentence for other offences in exchange for co-operating in the trial.

“[The] breach of the duty of disclosure could realistically have affected the reasoning of the jury as to the verdict of guilty that was returned and thus gives rise to a miscarriage of justice,” prosecutors told the court.

Chamma and Hicks had been accused of committing the opportunistic robbery with a third man after being told Hunter had a large sum of cash at his Toongabbie home.

Hicks stabbed Hunter, but Chamma knew of the knife and helped create a handmade sheath beforehand, Justice Sarah McNaughton found when sentencing the pair in September 2023.

At the time, Hicks was sentenced to 23 years’ imprisonment with a non-parole period of 16 years, while Chamma received 21 years with a non-parole period of 15 years and nine months.

Chamma’s successful appeal will see him head into a retrial.

He will be re-arraigned in the NSW Supreme Court on July 4.

The appeal court rejected Chamma’s further claims that the verdict of murder was unreasonable.

He argued he should be acquitted on this charge and sent back to a retrial for the lesser offence of manslaughter.

However, two of the three appeal judges found it was open to jurors to find him guilty of murder.

It was open for them to find he went ahead with the robbery despite knowing there was a probability that death or really serious injury could result, Justices Mark Leeming and Robertson Wright said.

In dissent, Justice Belinda Rigg said she would have acquitted Chamma of murder.

She said she could not be satisfied beyond reasonable doubt that he knew Hicks would use the knife intending to kill or cause grievous bodily harm.